The present invention relates to improvements in a guide rail unit for an automatic seat belt mounted at a front seat for a vehicle.
In an existing automatic seat belt unit mounted at a front seat for a vehicle, the outer side end of a seat belt is led from the top of a center pillar through a roof side rail to the top of a front pillar upon opening of an automotive door, the seat belt is disposed to an occupant non-restricting position, the outer side end is guided from the top of the front pillar again through the roof side rail to the top of the center pillar upon closing of the door, and the seat belt is disposed to an occupant restricting position.
In the above-described automatic seat belt unit, the guide rail of the seat belt is arranged while the seat belt is moved from the top of the center pillar through the roof side rail to the top of the front pillar. The conventional guide rail is variously constructed as shown in FIGS. 5 to 9.
More particularly, in the automatic seat belt represented by FIG. 5, a guide shoe 4 is bonded on the inner surface of the guide groove 3 of a seat belt slider 2 in the rail body 1 of a guide rail. Thus, the rail body 1 should be increased in size, and the bracket is also increased in size. When this seat belt is mounted at a center or front pillar of narrow width, it has such a disadvantage that the external appearance is obviated since the seat belt is not contained in the narrow width of the pillar. Further, due to the length l of the guide rail 1, when the guide rail 1 is bent at the transition from the center or front pillars to the roof side rail, the sectional shape of the guide rail 1 is collapsed, and the seat belt slider 2 cannot advantageously slide smoothly.
In the automatic seat belt represented by FIG. 6, the rail body 5 of the guide rail is increased in size in the same manner as that shown in FIG. 5 because the guide arm 7 of the seat belt slider 6 and a guide groove 9 of a slide roller 8 are formed, and this also has the similar disadvantage to that in FIG. 5.
In the automatic seat belt represented by FIG. 7, a mounting flange 12 is integrally extended from the rail body 11 formed with the guide groove 10 of the seat belt slider in the guide rail structure. Thus, the size l is increased, and this also has the similar disadvantage to that in FIG. 5.
In the automatic seat belt represented by FIG. 8, the rail body 13 is interposed between anchor brackets 14 and 15, and mounting holes 18 and 19 are opened at the mounting flanges 16 and 17 which are extended from the anchor brackets 14 and 15, respectively. In this manner, the size l is similarly increased as the above examples, and similar disadvantage is contained to that in FIG. 5.
In the seat belt illustrated in FIG. 9, the guide rail is split into a slide rail 21 secured to a roof side rail 20 and a guide rail 22 secured to a slide rail 21, the slide rollers 24, 25 of the seat belt slider 23 are rolled on the slide rail 21, and the seat belt slider 23 is slidably reciprocated by the slider drive tape 26 by the guide rail 22. Thus, the size l is similarly increased, similar disadvantage to that in FIG. 5 is incorporated, and the structure is further complicated making expense another of its drawbacks.